4,842 research outputs found
High Tc Superconductors -- A Variational Theory of the Superconducting State
We use a variational approach to gain insight into the strongly correlated
d-wave superconducting state of the high Tc cuprates at T=0. We show that
strong correlations lead to qualitatively different trends in pairing and phase
coherence: the pairing scale decreases monotonically with hole doping while the
SC order parameter shows a non-monotonic dome. We obtain detailed results for
the doping-dependence of a large number of experimentally observable
quantities, including the chemical potential, coherence length, momentum
distribution, nodal quasiparticle weight and dispersion, incoherent features in
photoemission spectra, optical spectral weight and superfluid density. Most of
our results are in remarkable quantitative agreement with existing data and
some of our predictions, first reported in Phys. Rev. Lett. {\bf 87}, 217002
(2001), have been recently verified.Comment: (Minor revisions, 1 figure added, version to appear in PRB) 23 RevTeX
pages, 11 eps figs, long version of cond-mat/0101121, contains detailed
comparisons with experiments, analytical insights, technical aspects of the
calculation, and comparison with slave boson MF
Adverse Childhood Experiences & mental health – the urgent need for public health intervention in India
Global evidence has demonstrated that Adverse Childhood Experiences (ACEs) from the childhood significantly increase the risk of mental and physical health for an adult. The research linking ACE with health and wellbeing over past 2 decades has confirmed a dose-response relationship between the number of ACE experienced and the extent of impact on wellbeing. The source of ACE is the family, community, and the immediate environment and it causes long term risk for mental health with the potential to carry it over beyond the present generation. The findings are consistent across the developed and developing countries, and the evidence highlights the need for new elements beyond the 10 ACE elements in the pathbreaking original study.
India, with a population of more than 0.4 billion children and adolescents, and with one out seven Indians being affected by mental health issues, need urgent intervention in identifying, managing, and preventing the ACEs. This commentary reviews global research, summarizes the limited evidence available in India on ACE elements’ impact on mental health, and proposes a multi-pronged approach to identify, manage and prevent the mental health implications of ACE in India to preempt a major public health challenge
DENDRITIC CELL DIFFERENTIATION BLOCKED BY PRIMARY EFFUSION LYMPHOMA-RELEASED FACTORS IS PARTIALLY RESTORED BY INHIBITION OF P38 MAPK
To better understand the molecular mechanisms underlying the dendritic cell (DC) defects in cancer, we analyzed which signaling pathway is implicated in the abnormal monocyte differentiation into DC determined by the presence of Primary effusion lymphoma (PEL) released factors. Our results indicate that the DC, obtained in this condition, together with phenotypic abnormalities and reduced allostimulatory function, showed hyperphosphorylation of signal transducer and activator of transcription 3 (STAT3) and p38 mitogen-activated protein kinase (MAPK) molecules, in comparison to the DC differentiated in the absence of PEL-released factors. The inhibition of p38 MAPK but not of STAT3 phosphorylation, with specific inhibitors, was able to revert the effect of the PEL-released factors on the DC phenotype. This study suggests that p38 MAPK signaling pathway is an important contributor to the abnormal differentiation of DC in PEL
Student alienation and perceived organizational culture: A correlational study
It is generally expected that the students are supposed to gain an engaging and enriching experience throughout their journey of higher education. The educational institutions have to take up the responsibility to ensure that students are engaged meaningfully and are in a state of well-being. However, in the present scenario, students at colleges and universities have started to feel alienated from the campus life. Research shows that alienation levels are rising among the youth. Factors like stress, coping mechanism, restrictive parental behavior, peer pressure, academic performance, and organizational culture have an impact on alienation among the students. This study attempts to understand the relationship between student alienation and organizational culture in an educational institution. The study employed a descriptive correlational design and collected data from 600 under graduate students studying in a university. The study used student alienation scale and organizational culture assessment instrument to collect the survey data. Study revealed that there is a negative correlation between student alienation and organizational culture. There were 30% variation in student alienation is explained by different types of organizational culture. Clan culture reduces student alienation compared to hierarchy culture. The researchers urge for further research to identify ideal organizational cultures that can promote student engagement and student well-being
Theoretical studies of the phase transition in the anisotropic 2-D square spin lattice
The phase transition occurring in a square 2-D spin lattice governed by an
anisotropic Heisenberg Hamiltonian has been studied according to two recently
proposed methods. The first one, the Dressed Cluster Method, provides excellent
evaluations of the cohesive energy, the discontinuity of its derivative around
the critical (isotropic) value of the anisotropy parameter confirms the
first-order character of the phase transition. Nevertheless the method
introduces two distinct reference functions (either N\'eel or XY) which may in
principle force the discontinuity. The Real Space Renormalization Group with
Effective Interactions does not reach the same numerical accuracy but it does
not introduce a reference function and the phase transition appears
qualitatively as due to the existence of two domains, with specific fixed
points. The method confirms the dependence of the spin gap on the anisotropy
parameter occurring in the Heisenberg-Ising domain
A Representation of Symmetry Generators for the Type IIB Superstring on a Plane Wave in the U(4) Formalism
We calculate the symmetry currents for the type IIB superstring on a
maximally supersymmetric plane wave background using the N=(2,2)
superconformally covariant U(4) formulation developed by Berkovits, Maldacena
and Maoz. An explicit realization of the U(4) generators together with 16
fermionic generators is obtained in terms of the N=(2,2) worldsheet fields.
Because the action is no longer quadratic, we use a light-cone version to
display the currents in terms of the covariant worldsheet variables.Comment: 9 pages, harvmac, Corrected some typographical errors, Added
reference
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